Three-roll mill and mechanism for adjusting the intermediate roll



Spt. 30, 1958 Filed Aug. 21, 1956 E. F. BEACH ET AL THREE-ROLL MILL ANDMECHANISM FOR ADJUSTING THE INTERMEDIATE ROLL.

3 Sheets-Sheet 1 Sept. 30, 1958 E. P. BEACH ETAL 2,854,195

' THREE-ROLL MILL AND MECHANISM FOR ADJUSTING THE INTERMEDIATE ROLL IFiled Aug. 21, 1956 5 Sheets-Sheet 2 Sept. 30, 1958 E. P. BEACH ETAL2,854,196

, THREE-ROLL MILL AND MECHANISM FOR ADJUSTING THE INTERMEDIATE ROLLFiled Aug. 21, 1956 3 Sheets-Sheet 5 THREE-ROLL MILL AND MECHANISM FURAD- JUSTING THE INTERMEDIATE RGLL Eric Procter Beach, Barrow-in-Furness,and George Locldey, Ulverston, England, assignors to Viclrers-Arrnstrongs (Engineers) Limited, London, England, a British companyApplication August 21, 1956, Serial No. 635,367

Claims priority, application Great Britain August 22, 1955 Claims. (Cl.241-111) This invention relates to three-roll mills of the kind whichare arranged so that material to be ground is passed firstly between oneroll and a second roll and then between the second roll and a thirdroll, the axes of the three rolls being parallel.

According to the present invention there is provided a three-roll millof the kind referred to in which the second roll is carried by adjustingmechanism arranged for moving the second roll towards or away from aplane that includes the axes of said one and third rolls, whereby theclearances between the second roll and each of the other two aresimultaneously decreased or increased respectively, the adjustingmechanism also being arranged for moving the second roll towards andaway from each of the other two rolls individually, so that theclearance between said one and said second roll can be increased whilstat the same time the clearance between said second and said third rollsis decreased, and vice versa.

It is to be understood that in some cases the second roll may contactthe other two rolls so that there are no clearances between the rolls.Where this is so references to increase or decrease of clearance shouldbe replaced by decrease or increase of pressure.

For a better understanding of the invention, and to show how the samemay be carried into effect, reference will now be made to theaccompanying drawings, in which:

Figure l is a sectional side elevation of part of a three-roll mill, thesection being taken on line I-l of Figure 2 and certain parts beingomitted,

Figure 2 is a part sectional front elevation of the mill of Figure 1,the section being taken on line llll of Figure 1 and certain parts beingomitted, and

Figure 3 is a sectional view taken on the line IIIIH of Figure 1.

The mill has a bed (not shown) that carries two side frames 1, 2 (shownin chain-dot outline) by which the three rolls 3, 4 and 5 of the millare carried. The three rolls 3, 4, 5 are of the same diameter and theiraxes are parallel. The rolls 3 and 5 are rotatably mounted directly inthe side frames 1, 2 and rotate about fixed centres 6, 7 respectively.The roll is spaced laterally from the roll 3 and is slightly higher thanthe roll 3, the distance between the axes of centres 6 and 7 of therolls 3 and 5 being slightly less than twice the diameter of one of therolls, so that the roll 4 cannot pass between the rolls 3 and 5. Thecentral roll 4 is carried, with its centre 8 above the plane joining theaxes 6 and 7 of the rolls 3 and 5, by two bearings 9, the housings 10 ofwhich are supported by mechanism that permits adjustment of the roll 4with respect to the rolls 3 and 5. Each housing 10 has two upwardlydirected arms 1?. that are pivotally secured by a pin 12 to an arm 13 ofa bellcrank lever 14. The bellcrank lever 14 is pivotally secured to theadjacent side frame 1 or 2 by a pin 15 parallel to the axes of the rolls3, 4 and 5. The arm 13 effectively extends approximately horizontallyand the other arm 16 of the bellcrank lever 14 extends approxi- Statsatent mately vertically upwardly. The free end 16A of the arm 16 isbifurcated and rotatably carries a pin 17 that is parallel to the rollaxes 6, 7, 8. The pin 17 has a threaded hole 18 therethroughperpendicular to the axis of the pin 17 and a long horizontal bolt 19 isthreadedly engaged in this hole 18. The free end of the bolt 19 ispassed through and threadedly engages with a pin 20 which is parallel tothe pin 17. The pin 20 is rotatably mounted in an upright lever 21, thelower end of which is pivotally secured by a pin 22 to the adjacent sideframe 1 or 2. The bolt 19 is passed through holes 21A in the lever 21,these holes being tapered to permit relative angular movement of thelever 21 and bolt 19 about the axis of the pin 20. The upper end of thelever 21 has a vertical slot 23 in which a sliding block 24 is located.An eccentric pin 25 on one end of a cross-shaft 26 is engaged in a hole27 in the sliding block 24. The crossshaft 26, which is parallel to theroll axes 6, 7 and 8, is supported by the two side'fratnes 1 and 2 andhas two eccentric pins 25, one at each end thereof, for co-operatingwith the sliding blocks 24 at each end of the roll 4. The shaft 26 has adownwardly extending lever 28 keyed thereto near the right-hand end(Figure 2) of the shaft 26. The free end of this lever 28 is pivotallysecured to one end of an adjusting link 29 disposed parallel to thebolts 19. The other end of the link 29 is pivotally secured to the freeend of an upwardly extending lever 39 keyed to a shaft 31 that ismounted in the side frame 1 and has an approximately horizontaloperating handle 32 fixed thereon. This handle 32 has ratchet and pawlmechanism 33 associated therewith for securing the mechanism associatedwith the sliding blocks 24 in any desired position.

Each bearing housing 10 has an arm 34 extending downwardly therefrom ina direction diametrally opposite to that of the arms 11. A slot 35extends from the free end of the arm 34 towards the axis 8 of the roll4. A sliding block 36 is located in this slot 35 and an eccentric pin 37on a short shaft 38 pivotally supported in the adjacent side frame 1 or2 passes through a hole 39 in this sliding block 36. The short shaft 38is parallel to the roll axes 6, 7 and 8 and has a gear segment 43 keyedthereon, this gear segment 40 co-operating with a worm 41 that is fixedon a shaft 42 carried by brackets 3 attached to the adjacent side frame1 or 2. The shaft 42 is horizontal and has a handwheel 44 thereon.

It will be understood, therefore, that the adjusting mechanism has oneoperating handle 32 and two hand- Wheels 44 for adjusting the positionof the centre roll 4.

The mill described above is used for grinding materials used, forexample, in the paint, printing-ink, chocolate, soap and plasticindustries. The centre roll 4 is brought into, or almost into, contactwith the rolls 3 and 5 by operation of the handle 32 and the material ispassed firstly between the rolls 3 and 4. and is subsequently passedbetween the rolls 4 and 5, the material being ground as it passesbetween the rolls. Movement of the operating handle 32 downwardly causesthe free ends of the arms 13 of the bellcrank levers 14, to be movedupwardly through the lever and link arrangements that include the shaft31, lever 39, link 29, lever 23, shaft 26, eccentric pins 25, blocks 24,levers 21 and bolts 19. The centre roll 4 is thus withdrawn from therolls 3 and 5, the centre roll 4 being guided during such upwardmovement by the slots 35 in the arms 34 which slots 35 slide on theblocks 36 that are at this time in a fixed position. When the operatinghandle 32 is moved upwardly the centre roll 4, through the intermediaryof said lever and link arrangements, is moved downwardly until itcontacts or almost contacts the rolls 3 and 5. The pressures orclearances between the rolls 3 and 4 and between the rolls 4 and 5 areadjusted by operation of the two handwheels 44. When the two handwheels44 are turned in one direction, the gear segments 40 cause the eccentricpins 37 on the short shafts 39 to swing in an arc towards the roll 3,the roll 4 swinging about the axis of the pins 12 that connect the arms11 and the bellcranklevers 14. Hence the clearance between the rolls 3and 4 is decreased (or the pressure increased) whilst the clearancebetween the rolls 4 and 5 is increased (or the pressure decreased). Whenthe two handwheels 44 are turned in the opposite direction the roll 4 ismoved to decrease the clearance (or increase the pressure) between therolls 4 and 5 and increase the clearance (or decrease the pressure)between the rolls 3 and 4. b

Although in the embodiment described above the second roll is adjustedthrough the intermediary of mechanical linkages, it is to be understoodthat the second roll could, if desired, be moved through theintermediary of other means, for example, hydraulic mechanism.

We claim:

1. A three-roll mill comprising first, second and third rolls arrangedin series the axes of which are parallel, the first and third rollsbeing mounted for rotation about fixed axes, the axis of the second rollbeing offset with respect to a plane which includes the axes of thefirst and third rolls and the diameter of the second roll being greaterthan the shortest distance between the first and third rolls,adjustingtmechanism carrying said second roll for moving the second rolltoward and away from the plane that includes the axes of the first andthird rolls to respectively and simultaneously decrease or increase theclearances between the second roll and each of the other two rolls, theadjusting mechanism including means for moving the second roll towardand away from each of the other two rolls individually, whereby theclearance between the first and second rolls can be increased while theclearance between the second and third rolls is simultaneouslydecreased, and vice versa.

2. A mill as claimed in claim 1, wherein'the second roll is carried ateach end thereof by a bearing, the housings of the bearings beingpivoted about a pivot axis ofi-set to one side of the axis of the secondroll, and wherein each housing at the opposite side of the axis of thesecond roll is connected to the adjusting mechanism through a pin andslot connection, the slot being directed towards the axis of the secondroll, and the adjusting mechanism being arranged for moving said pivotaxis towards and away from said plane and for moving the pin and slotconnections towards and away from said other two rolls individually.

3. A mill as claimed in claim 2, wherein the slot of each pin and slotconnection is in the associated housing, the pin being constituted by ablock extending in the slot and connected to. the adjusting mechanismfor movement towards and away from said other two rolls, the arrangementbeing such that when the pivot axis is moved towards or away from saidplane the housings slide on said blocks and such that when the blocksare moved the housings pivot about said pivot axis.

4. A mill as claimed in claim 3, wherein the adjusting mechanismincludes a single manually operated member for adjusting the position ofsaid pivot axis and two manually operated members, one for each of saidconnections, for adjusting the positions of the latter individually.

5. A mill as claimed in claim 1, wherein the second roll is carried ateach end thereof by a bearing, the housings of the bearings beingpivoted about a pivot axis oflfset to one side of the axis of the secondroll, each housing at the opposite side of the axis of the second rollbeing connected to the adjusting mechanism through a 7 pin and slotconnection, the slot being directed towards the axis of the second roll,the adjusting mechanism being arranged for moving said pivot axistowards and away from said plane and for moving the pin and slotconnections towards and away from said othertwotrolls individually, andthe adjusting mechanism including a single manually operated member foradjusting the position of said pivot axis and two manually operatedmembers, one for eachtof said connections, for adjusting the positionsof the latter individually.

References Cited in the file of this patent UNITED STATES PATENTS881,287 Baker Mar. 10, 1908

